Light-emitting device including organometallic compound, electronic apparatus including the light-emitting device, and the organometallic compound

Abstract

A light-emitting device including an organometallic compound represented by Formula 1, an electronic apparatus including the light-emitting device, and the organometallic compound represented by Formula 1 are provided:

What is claimed is: 
     
         1 . A light-emitting device comprising:
 a first electrode;   a second electrode facing the first electrode;   an interlayer between the first electrode and the second electrode and comprising an emission layer; and   an organometallic compound represented by Formula 1:   
       
         
           
           
               
               
           
         
         wherein, in Formula 1, 
         M 1  is platinum (Pt), palladium (Pd), copper (Cu), silver (Ag), gold (Au), rhodium (Rh), ruthenium (Ru), osmium (Os), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu), terbium (Tb), or thulium (Tm), 
         ring CY 1 , ring CY 2 , and ring CY 4  are each independently a C 5 -C 30  carbocyclic group or a C 1 -C 30  heterocyclic group, 
         X 1 , X 2 , and X 4  are each independently C or N, 
         Y is *—C(R 6 )(R 7 )—*′, *—C(═O)—*′, *—C(═S)—*′, *—B(R 6 )—*′, *—N(R 6 )—*′, *—O—*′, *—P(R 6 )—*′, *—Si(R 6 )(R 7 )—*′, *—Se—*′, *—S—*′, *—S(═O)—*′, *—S(═O) 2 —*′, or *—Ge(R 6 )(R 7 )—*′, 
         L 1  to L 3  are each independently a single bond, *—C(R 1a )(R 1b )—*′, *—C(R 1a )═*′, *═C(R 1a )—*′, *—C(R 1a )═C(R 1b )—*′, *—C(═O)—*′, *—C(═S)—*′, *—C≡C—*′, *—B(R 1a )—*′, *—N(R 1a )—*′, *—O—*′, *—P(R 1a )—*′, *—Si(R 1a )(R 1b )—*′, *—P(═O)(R 1a )—*′, *—S—*′, *—S(═O)—*′, *—S(═O) 2 —*′, or *—Ge(R 1a )(R 1b )—*′, 
         a1 to a3 are each an integer from 1 to 3, 
         * and *′ each indicate a binding site to a neighboring atom, 
         R 1  to R 7 , R 1a , and R 1b  are each independently hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C 1 -C 60  alkyl group unsubstituted or substituted with at least one R 10a , a C 2 -C 60  alkenyl group unsubstituted or substituted with at least one R 10a , a C 2 -C 60  alkynyl group unsubstituted or substituted with at least one R 10a , a C 1 -C 60  alkoxy group unsubstituted or substituted with at least one R 10a , a C 5 -C 60  carbocyclic group unsubstituted or substituted with at least one R 10a , a C 1 -C 60  heterocyclic group unsubstituted or substituted with at least one R 10a , a C 6 -C 60  aryloxy group unsubstituted or substituted with at least one R 10a , a C 6 -C 60  arylthio group unsubstituted or substituted with at least one R 10a , —C(Q 1 )(Q 2 )(Q 3 ), —Si(Q 1 )(Q 2 )(Q 3 ), —Ge(Q 1 )(Q 2 )(Q 3 ), —N(Q 1 )(Q 2 ), —B(Q 1 )(Q 2 ), —C(═O)(Q 1 ), —S(═O) 2 (Q 1 ), or —P(═O)(Q 1 )(Q 2 ), 
         two or more selected from among a plurality of R 1 (s) are optionally bonded to each other to form a C 3 -C 60  carbocyclic group unsubstituted or substituted with at least one R 10a  or a C 1 -C 60  heterocyclic group unsubstituted or substituted with at least one R 10a , 
         two or more selected from among a plurality of R 2 (s) are optionally bonded to each other to form a C 3 -C 60  carbocyclic group unsubstituted or substituted with at least one R 10a  or a C 1 -C 60  heterocyclic group unsubstituted or substituted with at least one R 10a , 
         two or more selected from among a plurality of R 4 (s) are optionally bonded to each other to form a C 3 -C 60  carbocyclic group unsubstituted or substituted with at least one R 10a  or a C 1 -C 60  heterocyclic group unsubstituted or substituted with at least one R 10a , 
         R 6  and R 7  are optionally bonded to each other to form a C 3 -C 60  carbocyclic group unsubstituted or substituted with at least one R 10a  or a C 1 -C 60  heterocyclic group unsubstituted or substituted with at least one R 10a , 
         b1, b2, and b4 are each independently an integer from 1 to 10, 
         b3 is 1, 
         b5 is an integer from 1 to 3, 
         R 10a  is: 
         deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, or a nitro group; 
         a C 1 -C 60  alkyl group, a C 2 -C 60  alkenyl group, a C 2 -C 60  alkynyl group, or C 1 -C 60  alkoxy group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C 5 -C 60  carbocyclic group, a C 1 -C 60  heterocyclic group, a C 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, —Si(Q 11 )(Q 12 )(Q 13 ), —Ge(Q 11 )(Q 12 )(Q 13 ), —N(Q 11 )(Q 12 ), —B(Q 11 )(Q 12 ), —C(═O)(Q 11 ), —S(═O) 2 (Q 11 ), —P(═O)(Q 11 )(Q 12 ), or any combination thereof; 
         a C 3 -C 60  carbocyclic group, a C 1 -C 60  heterocyclic group, a C 6 -C 60  aryloxy group, or a C 6 -C 60  arylthio group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C 1 -C 60  alkyl group, a C 2 -C 60  alkenyl group, a C 2 -C 60  alkynyl group, a C 1 -C 60  alkoxy group, a C 3 -C 60  carbocyclic group, a C 1 -C 60  heterocyclic group, a C 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, —Si(Q 21 )(Q 22 )(Q 23 ), —Ge(Q 21 )(Q 22 )(Q 23 ), —N(Q 21 )(Q 22 ), —B(Q 21 )(Q 22 ), —C(═O)(Q 21 ), —S(═O) 2 (Q 21 ), —P(═O)(Q 21 )(Q 22 ), or any combination thereof; or 
         —Si(Q 31 )(Q 32 )(Q 33 ), —Ge(Q 31 )(Q 32 )(Q 33 ), —N(Q 31 )(Q 32 ), —B(Q 31 )(Q 32 ), —C(═O)(Q 31 ), —S(═O) 2 (Q 31 ), or —P(═O)(Q 31 )(Q 32 ), and 
         Q 1  to Q 3 , Q 11  to Q 13 , Q 21  to Q 23 , and Q 31  to Q 33  are each independently: 
         hydrogen; deuterium; —F; —Cl; —Br; —I; a hydroxyl group; a cyano group; a nitro group; 
         or a C 1 -C 60  alkyl group, a C 2 -C 60  alkenyl group, a C 2 -C 60  alkynyl group, a C 1 -C 60  alkoxy group, a C 3 -C 60  carbocyclic group, a C 1 -C 60  heterocyclic group, a C 7 -C 60  arylalkyl group, or a C 2 -C 60  heteroarylalkyl group, each unsubstituted or substituted with deuterium, —F, a cyano group, a C 1 -C 60  alkyl group, a C 1 -C 60  alkoxy group, a phenyl group, a biphenyl group, a pyridinyl group, a pyrimidinyl group, a pyridazinyl group, a pyrazinyl group, a triazinyl group, or any combination thereof. 
       
     
     
         2 . The light-emitting device of  claim 1 , wherein,
 the first electrode is an anode,   the second electrode is a cathode,   the interlayer further comprises a hole transport region between the first electrode and the emission layer and an electron transport region between the emission layer and the second electrode,   the hole transport region comprises a hole injection layer, a hole transport layer, an emission auxiliary layer, an electron blocking layer, or any combination thereof, and   the electron transport region comprises a hole blocking layer, an electron transport layer, an electron injection layer, or any combination thereof.   
     
     
         3 . The light-emitting device of  claim 1 ,
 wherein the emission layer comprises the organometallic compound represented by Formula 1.   
     
     
         4 . The light-emitting device of  claim 1 ,
 wherein the emission layer comprises a host and a dopant, and   the dopant comprises the organometallic compound represented by Formula 1.   
     
     
         5 . The light-emitting device of  claim 1 ,
 wherein the interlayer comprises:   i) a first compound which is the organometallic compound represented by Formula 1; and   ii) a second compound comprising at least one IT electron-deficient nitrogen-containing C 1 -C 60  cyclic group, a third compound comprising a group represented by Formula 3, a fourth compound which is to emit delayed fluorescence, or any combination thereof,   the first compound, the second compound, the third compound, and the fourth compound being different from each other:   
       
         
           
           
               
               
           
         
         ring CY 71  and ring CY72 in Formula 3 being each independently a π electron-rich C 3 -C 60  cyclic group or a pyridine group, 
         X 71  in Formula 3 being a single bond or a linking group comprising O, S, N, B, C, Si, or any combination thereof, 
         * in Formula 3 indicating a binding site to a neighboring atom in the third compound, and 
         Compounds CBP and mCBP being excluded from the third compound: 
       
       
         
           
           
               
               
           
         
       
     
     
         6 . The light-emitting device of  claim 5 ,
 wherein the interlayer comprises the first compound and the fourth compound, and   the fourth compound is a compound comprising at least one cyclic group comprising a boron (B) atom and a nitrogen (N) atom each as a ring-forming atom.   
     
     
         7 . An electronic apparatus comprising the light-emitting device of  claim 1 . 
     
     
         8 . The electronic apparatus of  claim 7 , further comprising
 a thin-film transistor,   wherein the thin-film transistor comprises a source electrode and a drain electrode, and   the first electrode of the light-emitting device is electrically connected to the source electrode or the drain electrode of the thin-film transistor.   
     
     
         9 . An organometallic compound represented by Formula 1: 
       
         
           
           
               
               
           
         
         wherein, in Formula 1, 
         M 1  is platinum (Pt), palladium (Pd), copper (Cu), silver (Ag), gold (Au), rhodium (Rh), ruthenium (Ru), osmium (Os), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu), terbium (Tb), or thulium (Tm), 
         ring CY 1 , ring CY 2 , and ring CY 4  are each independently a C 5 -C 30  carbocyclic group or a C 1 -C 30  heterocyclic group, 
         X 1 , X 2 , and X 4  are each independently C or N, 
         Y is *—C(R 6 )(R 7 )—*′, *—C(═O)—*′, *—C(═S)—*′, *—B(R 6 )—*′, *—N(R 6 )—*′, *—O—*′, *—P(R 6 )—*′, *—Si(R 6 )(R 7 )—*′, *—Se—*′, *—S—*′, *—S(═O)—*′, *—S(═O) 2 —*′, or *—Ge(R 6 )(R 7 )—*′, 
         L 1  to L 3  are each independently a single bond, *—C(R 1a )(R 1b )—*′, *—C(R 1a )═*′, *═C(Ra)—*′, *—C(R 1a )═C(R 1b )—*′, *—C(═O)—*′, *—C(═S)—*′, *—C≡C—*′, *—B(R 1a )—*′, *—N(R 1a )—*′, *—O—* *—P(R 1a )—*′, *—Si(R 1a )(R 1b )—*′, *—P(═O)(R 1a )—*′, *—S—*′, *—S(═O)—*′, *—S(═O) 2 —*′, or *—Ge(R 1a )(R 1b )—*′, 
         a1 to a3 are each an integer from 1 to 3, 
         * and *′ each indicate a binding site to a neighboring atom, 
         R 1  to R 7 , R 1a , and R 1b  are each independently hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C 1 -C 60  alkyl group unsubstituted or substituted with at least one R 10a , a C 2 -C 60  alkenyl group unsubstituted or substituted with at least one R 10a , a C 2 -C 60  alkynyl group unsubstituted or substituted with at least one R 10a , a C 1 -C 60  alkoxy group unsubstituted or substituted with at least one R 10a , a C 3 -C 60  carbocyclic group unsubstituted or substituted with at least one R 10a , a C 1 -C 60  heterocyclic group unsubstituted or substituted with at least one R 10a , a C 6 -C 60  aryloxy group unsubstituted or substituted with at least one R 10a , a C 6 -C 60  arylthio group unsubstituted or substituted with at least one R 10a , —C(Q 1 )(Q 2 )(Q 3 ), —Si(Q 1 )(Q 2 )(Q 3 ), —Ge(Q 1 )(Q 2 )(Q 3 ), —N(Q 1 )(Q 2 ), —B(Q 1 )(Q 2 ), —C(═O)(Q 1 ), —S(═O) 2 (Q 1 ), or —P(═O)(Q 1 )(Q 2 ), 
         two or more selected from among a plurality of R 1 (s) are optionally bonded to each other to form a C 3 -C 60  carbocyclic group unsubstituted or substituted with at least one R 10a  or a C 1 -C 60  heterocyclic group unsubstituted or substituted with at least one R 10a , 
         two or more selected from among a plurality of R 2 (s) are optionally bonded to each other to form a C 3 -C 60  carbocyclic group unsubstituted or substituted with at least one R 10a  or a C 1 -C 60  heterocyclic group unsubstituted or substituted with at least one R 10a , 
         two or more selected from among a plurality of R 4 (s) are optionally bonded to each other to form a C 3 -C 60  carbocyclic group unsubstituted or substituted with at least one R 10a  or a C 1 -C 60  heterocyclic group unsubstituted or substituted with at least one R 10a , 
         R 6  and R 7  are optionally bonded to each other to form a C 3 -C 60  carbocyclic group unsubstituted or substituted with at least one R 10a  or a C 1 -C 60  heterocyclic group unsubstituted or substituted with at least one R 10a , 
         b1, b2, and b4 are each independently an integer from 1 to 10, 
         b3 is 1, 
         b5 is an integer from 1 to 3, 
         R 10a  is: 
         deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, or a nitro group; 
         a C 1 -C 60  alkyl group, a C 2 -C 60  alkenyl group, a C 2 -C 60  alkynyl group, or C 1 -C 60  alkoxy group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C 3 -C 60  carbocyclic group, a C 1 -C 60  heterocyclic group, a C 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, —Si(Q 11 )(Q 12 )(Q 13 ), —Ge(Q 11 )(Q 12 )(Q 13 ), —N(Q 11 )(Q 12 ), —B(Q 11 )(Q 12 ), —C(═O)(Q 11 ), —S(═O) 2 (Q 11 ), —P(═O)(Q 11 )(Q 12 ), or any combination thereof; 
         a C 3 -C 60  carbocyclic group, a C 1 -C 60  heterocyclic group, a C 6 -C 60  aryloxy group, or a C 6 -C 60  arylthio group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C 1 -C 60  alkyl group, a C 2 -C 60  alkenyl group, a C 2 -C 60  alkynyl group, a C 1 -C 60  alkoxy group, a C 3 -C 60  carbocyclic group, a C 1 -C 60  heterocyclic group, a C 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, —Si(Q 21 )(Q 22 )(Q 23 ), —Ge(Q 21 )(Q 22 )(Q 23 ), —N(Q 21 )(Q 22 ), —B(Q 21 )(Q 22 ), —C(═O)(Q 21 ), —S(═O) 2 (Q 21 ), —P(═O)(Q 21 )(Q 22 ), or any combination thereof; or 
         —Si(Q 31 )(Q 32 )(Q 33 ), —Ge(Q 31 )(Q 32 )(Q 33 ), —N(Q 31 )(Q 32 ), —B(Q 31 )(Q 32 ), —C(═O)(Q 31 ), —S(═O) 2 (Q 31 ), or —P(═O)(Q 31 )(Q 32 ), and 
         Q 1  to Q 3 , Q 11  to Q 13 , Q 21  to Q 23 , and Q 31  to Q 33  are each independently: hydrogen; deuterium; —F; —Cl; —Br; —I; a hydroxyl group; a cyano group; a nitro group; or a C 1 -C 60  alkyl group, a C 2 -C 60  alkenyl group, a C 2 -C 60  alkynyl group, a C 1 -C 60  alkoxy group, a C 3 -C 60  carbocyclic group, a C 1 -C 60  heterocyclic group, a C 7 -C 60  arylalkyl group, or a C 2 -C 60  heteroarylalkyl group, each unsubstituted or substituted with deuterium, —F, a cyano group, a C 1 -C 60  alkyl group, a C 1 -C 60  alkoxy group, a phenyl group, a biphenyl group, a pyridinyl group, a pyrimidinyl group, a pyridazinyl group, a pyrazinyl group, a triazinyl group, or any combination thereof. 
       
     
     
         10 . The organometallic compound of  claim 9 ,
 wherein ring CY 1 , ring CY 2 , and ring CY 4  are each independently a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, a triphenylene group, a pyrene group, a chrysene group, a cyclopentadiene group, a 1,2,3,4-tetrahydronaphthalene group, a thiophene group, a furan group, an indole group, a benzoborole group, a benzophosphole group, an indene group, a benzosilole group, a benzogermole group, a benzothiophene group, a benzoselenophene group, a benzofuran group, a carbazole group, a dibenzoborole group, a dibenzophosphole group, a fluorene group, a dibenzosilole group, a dibenzogermole group, a dibenzothiophene group, a dibenzoselenophene group, a dibenzofuran group, a dibenzothiophene 5-oxide group, a 9H-fluorene-9-one group, a dibenzothiophene 5,5-dioxide group, an azaindole group, an azabenzoborole group, an azabenzophosphole group, an azaindene group, an azabenzosilole group, an azabenzogermole group, an azabenzothiophene group, an azabenzoselenophene group, an azabenzofuran group, an azacarbazole group, an azadibenzoborole group, an azadibenzophosphole group, an azafluorene group, an azadibenzosilole group, an azadibenzogermole group, an azadibenzothiophene group, an azadibenzoselenophene group, an azadibenzofuran group, an azadibenzothiophene 5-oxide group, an aza-9H-fluorene-9-one group, an azadibenzothiophene 5,5-dioxide group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a phenanthroline group, a pyrrole group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, a thiazole group, an isothiazole group, an oxadiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzothiazole group, a benzoxadiazole group, a benzothiadiazole group, a 5,6,7,8-tetrahydroisoquinoline group, or a 5,6,7,8-tetrahydroquinoline group.   
     
     
         11 . The organometallic compound of  claim 9 ,
 wherein ring CY 1  is an imidazole group, a benzimidazole group, an imidazopyridine group, an imidazopyrazine group, an imidazopyrimidine group, or an imidazopyridazine group, and   ring CY 2  is a benzene group, a naphthalene group, or a 1,2,3,4-tetrahydronaphthalene group.   
     
     
         12 . The organometallic compound  claim 9 ,
 wherein X 1  is C, X 2  is C, and X 4  is N.   
     
     
         13 . The organometallic compound of  claim 9 ,
 wherein a moiety represented by   
       
         
           
           
               
               
           
         
       
       in Formula 1 is a group represented by any one selected from among Formulae CY(1)-1 to CY(1)-12: 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         in Formulae CY(1)-1 to CY(1)-12, 
         R 10  to R 13  being each independently the same as described with respect to R 1  in Formula 1, 
         c10 being an integer from 1 to 4, 
         c11 being an integer from 1 to 3, 
         c12 being an integer of 1 or 2, and 
         * and *′ each indicating a binding site to a neighboring atom. 
       
     
     
         14 . The organometallic compound of  claim 9 ,
 wherein a moiety represented by   
       
         
           
           
               
               
           
         
       
       in Formula 1 is a group represented by any one selected from among Formulae CY(2)-1 to CY(2)-8: 
       
         
           
           
               
               
           
         
         in Formulae CY(2)-1 to CY(2)-8, 
         R 21  to R 23  being each independently the same as described with respect to R 2  in Formula 1, but each not hydrogen, and 
         *, *′ and *″ each indicating a binding site to a neighboring atom. 
       
     
     
         15 . The organometallic compound of  claim 9 ,
 wherein a moiety represented by   
       
         
           
           
               
               
           
         
       
       in Formula 1 is a group represented by any one selected from among Formulae CY(3)-1 to CY(3)-11: 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         in Formulae CY(3)-1 to CY(3)-11, 
         R 3 , R 5 , and b5 being each the same as described in Formula 1, 
         Z 1  being the same as described with respect to R 6  in Formula 1, 
         Z 2  being the same as described with respect to R 7  in Formula 1, 
         Z 1  and Z 2  being optionally bonded to each other to form a C 3 -C 60  carbocyclic group unsubstituted or substituted with at least one R 10b  or a C 1 -C 60  heterocyclic group unsubstituted or substituted with at least one R 10b , 
         Y 11  being C, Si, or Ge, 
         L 11  being *—C(R 6a )(R 7a )—*′, *—C(═O)—*′, *—C(═S)—*′, *—B(R 6a )—*′, *—N(R 6a )—*′, *—O—*′, *—P(R 6a )—*′, *—Si(R 6a )(R 7a )—*′, *—Se—*′, *—S—*′, *—S(═O)—*′, *—S(═O) 2 —*′, or *—Ge(R 6a )(R 7a )—*′, 
         R 31 , R 32 , R 6a , and R 7a  being each independently: hydrogen or the same as described with respect to R 10a  in Formula 1, 
         R 6a  and R 7a  being optionally bonded to each other to form a C 3 -C 60  carbocyclic group unsubstituted or substituted with at least one R 10b  or a C 1 -C 60  heterocyclic group unsubstituted or substituted with at least one R 10b , 
         R 10b  being each independently the same as described with respect to R 10a  in Formula 1, 
         c31 and c32 being each independently an integer from 1 to 4, and 
         *, *′, and *″ each indicating a binding site to a neighboring atom. 
       
     
     
         16 . The organometallic compound of  claim 9 ,
 wherein a moiety represented by   
       
         
           
           
               
               
           
         
       
       in Formula 1 is a group represented by any one selected from among Formulae CY(4)-1 to CY(4)-16: 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         in Formulae CY(4)-1 to CY(4)-16, 
         R 41  to R 44  being each independently the same as described with respect to R 4  in Formula 1, but each not hydrogen, and 
         * and *′ each indicate a binding site to a neighboring atom. 
       
     
     
         17 . The organometallic compound of  claim 9 ,
 wherein   L 1  and L 3  are each a single bond, and   L 2  is *—O—*′, *—S—*′, or *—N(R 1a )—*′.   
     
     
         18 . The organometallic compound of  claim 9 ,
 wherein R 1  to R 7 , R 1a , and R 1b  are each independently:   hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C 1 -C 20  alkyl group, or a C 1 -C 20  alkoxy group;   a C 1 -C 20  alkyl group or a C 1 -C 20  alkoxy group, each substituted with at least one of deuterium, —F, —Cl, —Br, —I, —CD 3 , —CD 2 H, —CDH 2 , —CF 3 , —CF 2 H, —CFH 2 , a hydroxyl group, a cyano group, a nitro group, a C 1 -C 10  alkyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a biphenyl group, a naphthyl group, a pyridinyl group, or a pyrimidinyl group;   a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a biphenyl group, a (C 1 -C 10  alkyl) phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzoisothiazolyl group, a benzoxazolyl group, a benzoisoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an azacarbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, an azafluorenyl group, or an azadibenzosilolyl group, each unsubstituted or substituted with at least one of deuterium, —F, —Cl, —Br, —I, —CD 3 , —CD 2 H, —CDH 2 , —CF 3 , —CF 2 H, —CFH 2 , a hydroxyl group, a cyano group, a nitro group, a C 1 -C 20  alkyl group, a C 1 -C 20  alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a biphenyl group, a (C 1 -C 10  alkyl) phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzoisothiazolyl group, a benzoxazolyl group, a benzoisoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, —Si(Q 31 )(Q 32 )(Q 33 ), —N(Q 31 )(Q 32 ), —B(Q 31 )(Q 32 ), —P(Q 31 )(Q 32 ), —C(═O)(Q 31 ), —S(═O) 2 (Q 31 ), or —P(═O)(Q 31 )(Q 32 ); or   —Si(Q 1 )(Q 2 )(Q 3 ), —N(Q 1 )(Q 2 ), —B(Q 1 )(Q 2 ), —C(═O)(Q 1 ), —S(═O) 2 (Q 1 ), or —P(═O)(Q 1 )(Q 2 ), and   Q 1  to Q 3  and Q 31  to Q 33  are each independently:   —CH 3 , —CD 3 , —CD 2 H, —CDH 2 , —CH 2 CH 3 , —CH 2 CD 3 , —CH 2 CD 2 H, —CH 2 CDH 2 , —CHDCH 3 , —CHDCD 2 H, —CHDCDH 2 , —CHDCD 3 , —CD 2 CD 3 , —CD 2 CD 2 H, or —CD 2 CDH 2 ; or   an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, a pyridazinyl group, a pyrazinyl group, or a triazinyl group, each unsubstituted or substituted with at least one of deuterium, a C 1 -C 10  alkyl group, a phenyl group, a biphenyl group, a pyridinyl group, a pyrimidinyl group, a pyridazinyl group, a pyrazinyl group, or a triazinyl group.   
     
     
         19 . The organometallic compound of  claim 9 ,
 wherein the organometallic compound is represented by Formula 1-1 or 1-2:   
       
         
           
           
               
               
           
         
         in Formulae 1-1 and 1-2, 
         M 1 , ring CY 2 , ring CY 4 , X 2 , X 4 , Y, L 1  to L 3 , a1 to a3, R 2  to R 5 , and b2 to b5 being each the same as described in Formula 1, and 
         R 11  to R 17  being each independently the same as described with respect to R 1  in Formula 1. 
       
     
     
         20 . The organometallic compound of  claim 9 ,
 wherein the organometallic compound is any one selected from among Compounds 1 to 200: